This proposal requests support to purchase a Zeiss LSM 710 Spectral Confocal Microscope for use at Children's Hospital Oakland Research Institute (CHORI) to facilitate an array of projects that mainly involve microscopy of live cells. Nine major users and a total of 16 NIH-funded projects at CHORI will immediately benefit from this instrument. The requested instrument is configured to support cellular localization of signals and their physiological functions in live cells. This will be made possible by environmental controls (temperature, CO2) on the stage of the microscope, continuous time-lapse recording capabilities, and a 3-channel spectral detector including ratio imaging capabilities. There is no confocal microscope at CHORI and no other high-end microscope. Currently, projects requiring microscopy are done off-site, mainly at the microscopy facilities at UC Berkeley, which is located in driving distance from CHORI. These fee-for-service instruments are in high demand, which creates a shortage of the large time blocks needed by CHORI investigators, in particular for live cell imaging. In view of the time-sensitive nature of these experiments and the difficulty of transporting live cells between institutions, the installation of a confocal microscope at CHORI for live cell imaging will enhance an array of ongoing NIH-funded projects, including research in the areas of cystic fibrosis, airway biology, meningitis vaccine development, sphingosine metabolism and cancer biology, pathogenesis of Chlamydia, lipoprotein and lipid biology, and micronutrient research, and skin cancer.. After extensive consultation with external microscopy experts and consideration of the available microscopes, the Zeiss LSM 710 was identified as the optimal system from a number of competing confocal systems by an internal microscopy committee that was founded at CHORI to establish and organize a user base and develop the structures necessary for an institutional microscopy core. The selected system is highly versatile and expandable if the need arises. All identified major users are experienced in using various Zeiss confocal microscopes, and there is microscopy expertise at CHORI to operate and maintain the proposed instrument. The requested Zeiss LSM 710 is one of the most advanced and sensitive instruments in its class and will complement other confocal microscopes available in the area. This microscope will significantly advance the current projects at CHORI and will add to the pool of shared instruments available.